Grinding fixture



Nov. 14, 1967 A. ROCHELEAU GRINDING FIXTURE Filed June 22, 1965 INVENTOR LEOPOLD A. ROCHELEAU ATTORNEY United States Patent 3,352,068 GRINDING FIXTURE Leopold A. Rocheleau, 650 N. Main St., Leominster, Mass. 01453 Filed June 22, 1965, Ser. No. 465,875 1 Claim. (Cl. 51-225) ABSTRACT F THE DISCLGSURE A tool grinding fixture comprising a cylindrical bushing in a bore in a housing, the spindle having -a smooth, cylindrical outer surface, conforming to a like surface on the bushing, and Imeans for leading air under pressure through a wall of the housing and circumferentially about the bushing, including a plurality of air passages between the exterior surface of the bushing and the interior surface of the housing, which passages extend in a longitudinal direction from a central point to prov-ide substantially the entire length of the bushing with interior air pressure, the passages terminating in ports directed to the interior surface of the bushing against the exterior surface of the spindle, providing a positive aircushion for the spindle.

This invention relates to a new and improved universal grinding fixtures particularly adapted for sharpening tools and reference is hereby lmade t-o my prior United States Patents Nos. 2,484,590 and 2,710,498.

The principal `object of the invention resides in the provision of a new and improved air cushioned spindle bearing the construction of which is such that the fixture may be used with o r without air connected to it, but with the air pressure connected, the spindle is mounted substantially without friction; the provision -of an air cushionedl spindle bearing vwhich is substantially cylindrical from end to'end Vthereof and does not require prior art tapering devices, etc. so that it is more ehcient and more easily manufactured and operated.

Other objects of the invention reside in the provision of new and improved gauging surfaces provided thereon, new and improved mounts for the tooth rest assembly and the indexing lock bracket assembly providing against injury or deleterious effect on the spindle itself.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which:

FIG. 1 is a view in front elevation illustrating the new fixture;

FIG. 2 is an end view of the housing, bushing and spindle looking in the direction of arrow 2 in FIG. l;

FIG. 3 is a longitudinal sectional view with parts lbroken away and in section, and

FIG. 4 is a rear view of the housing.

In disclosing the invention, there is provided any kind of base or the like generally indicated at 10 and this may be provided with -means for clamping it in position on a grinder worktable or the like. The base is provided with swivel mounting means for swivelly mounting a bracket 12, this bracket having a standard offset from the center thereof as at 14. The standard mounts the spindle bushing housing which is generally indicated by the reference numeral 16. The base is provided with degrees to show the amount of swivel positioning of the base and spindle bushing housing on a vertical :axis and the housing itself is swiveled on the standard on a horizontal axis.

The housing 16 is provided with at least three accurately finished surfaces which are indicated at 18, these being located at the top, the side and the bottom for the purpose of 4providing a gauge for the positioning of the center height gauge generally indicated at 20. This is ICC for positioning the [guide finger 22, a tooth rest and gauge, which is universally adjustable relative to the chuck in the hou-sing for the purpose of accurately positioning the respective teethfon a cutter which is to be sharpened. By the use of the three different surfaces 18, this can be done in any position of the guide linger 22. The gauge plate 24 on the center height gauge 20 is adjustable by swinging plate 24 so as to set the cutting edges of cutters over or under the center line of spindle 30.

The tooth rest 22 is conveniently mounted on an annular split bracket 26 angularly adjustably mounted on the end of the housing 16 and clamped by a conventional screw, see FIG. 2. At the other end of the housing 16 is an index disc 27 and an index lock bracket 28, which can be applied and cla-mped to either end of the housing. The index disc and bracket are primarily Iused when the fixture is used as an indexing work head, the bracket 28 being angularly adjustable about the axis of spindle 30. The tooth rest bracket 26 is calibrated in degrees at two areas apart and the bracket is adjustable t-o any angular relation and there locked.

' To ,avoid any possible distortion to the spindle bushing 32, which -might cause the bushing to bind the spindle, the housing is counterbored at each end, leaving annular gaps 29 between the bushingy and the housing 16 in the areas where the brackets 26 and 28 are clamped.

The spindle 30 contains a conventional or commercial chuck for holding pieces to be worked on such as end mills, form cutters, etc., and it is mounted in an air cushion bushing 32 which is best shown in FIGS. 2 and 3.

As shown in FIG. 2, there is an air hose fitting 34 on the shank 35 of the spindle bushing housing 16 and this leads directly into the bore of the housing as at port 36, and any shop air connection can be applied to it. As shown herein, the interior of the spindle bushing housing is provided with a pair of annular spaced grooves 38, 38 intersecting the port'36 and these are for the purpose of conducting the air under pressure completely about the interi-or of the bore of the housing.

The bearing itself is substantially cylindrical. The interior surface thereof is indicated at 40 in FIG. 3 and fits with close tolerance in the bore of the housing so that the grooves 38 form a pair of parallel annular passages about the exterior surface of the bushing. The grooves 38 incidentally could also be formed in the exterior surface of the bushing itself but due to the thin wall thereof it is more practical to apply these grooves to the interiorv surface of the housing 16.

The spindle 30 fits neatly within the bushing and itself is cylindrical. With the air pressure not applied, the spindle may be moved where desired but under some degree of friction` The inlet port at 36 for the air intersects both of the 4grooves 38 and on the outer surface of the bushing communicating with grooves 3S are a plurality of groups of longitudinal parti-al grooves 4-2, 42 which lead the air from points adjacent the center of the bushing outwardly longitudinally toward the ends thereof. The longitudinal grooves 42 terminate in inwardly directed ports 44 which direct the air at the ends of the longitudinal grooves 42 against the surface of the spindle and thereby form a complete air cushion for the spindle, all of the grooves 42 being equal and the two grooves 38 likewise being equal.

The effect of this structure is that even though one end portion of the bushing should be loose and lose air, the other end portion will not become starved for lack of air which is being lost at the loose end, and therefore there is always an air cushion regardless of possible wear or looseness in the bushing and spindle so that one of the deficiencies of the prior art is overcome by the construc- 3 ion herein. The land 39 between grooves 38 separates the tir cushion into two separate systems.

The housing 16 may also be provided with a setscrew )r the like which preferably is provided with a point to :ngag'e' in similarly shaped holes 46, 46 arranged about ihe' periphery' of the: bushing so that the bushing is held n position against either axial or rotative motion. However, upon loosening the setscrew it will be clear that the bushing can be indexed: if this should become advisable iue to wear, etc.

The housing 16: is provided With annular end shoulders or the like' generally indicated at 48` and these rotatively carry' the tooth rest assembly bracket' 2'6 and the indexing lock bracket at 28l so that when these become clamped in position there 1s no pressure on the bushing or spindle but only' on the housing, and therefore no injury can be done the bushing nor can it be distorted in any Way so as to interfere with the smooth action of the spindle.

The bore of the spindle itself is arranged to provide for the collet, chuck or lany other member which is to be utilized and in FIG. 1 at -50 there is shown the collet draw bar of conventional construction.

It is thought that the construction and operation of the fixture will be clear. Although the device does not require the use :of the' air cushion, it is provided with means for accepting an extremely accurate and eflicient air cushion simply by connection to the shop air and the construction of the bushing provides this air to be evenly impressed upon the spindle at all sides thereof thereby truly mounting the same on a cushion of air so that there is no friction betweenl the spindle and its bushing. The

tooth rest finger 22 is quickly set for centralization with respect to the spindle by the use of gauge 20 at any one of the surfaces 18, depending upon where the finger 22 is desired to be placed, it being capable of being indexed a full 360 about the axis of the spindle. This assembly as Well as the indexing lock bracket at 28 are mounted on the housing to rotate the amount for indexing action on the housing, and not on the bushing, .as in prior art dievices, this having the desired effect of not interfering with the spindle at alll Ias described above.

Having thusA described my invention and the advantages thereof, I do` not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but What I claim is:

A tool Agrinding xture comprising a base, a standard on the base being angularly adjustable with relation to the base, a housing on the standard angularly adjustable therewith, a bore in said housing from end to end thereof, said bore being substantially cylindrical, a cylindrical bushing in the bore terminating generally coextensively with the ends of the housingat the ends of the bore, and a spindle in the bushing, said spindle having a smooth cylindrical outer surface conforming to a like [generally cylindrical inn-er surface for the bushing, means for leading air under pressure through a wall of the housing and circumferentially about the exterior of said bushing comprising a pair of spaced centerally located circumferential grooves in the bore of said housing and an air inlet extending through said housing and communicating withl said spaced grooves, and a plurality of ,groups of air passages between the exterior surface of the bushing and the interior surface of the housing communicating with said grooves, one` of said groups of passages extending generally in a longitudinal `direction from one of said 4grooves outwardly toward the closest end of the bushing and the other of said -groups of passages extending generally in a longitudinal direction from said other groove toward the other end of the bushing, said passages terminating in ports directed through the interior surface of the bushing against the exterior surface of the spindle and providing a positive air cushion for the spindle, certain of said ports being diametrically opposite each other.

References Cited UNITED STATES PATENTS 429,507 `6/ 1890 Conradson 308--240 X 2,023,764 12/ 1935 Howarth. 2,332,510 10/ 1943 Franzen 51-225 2,484,590 10/ 1949 Rocheleau 51-225 2,625,448 1/1953 Underwood 308-240 X 2,710,498 6/ 1955 Rocheleau 51-225 3,030,744 4/1962 Mueller 51-225 3,118,384 1/1964 Sence 308-122 X 3,131,977 5/1964 Wirtz 308-240 FOREIGN PATENTS 1,088,917 9/ 1955 France.

704,028 2/1954 Great Britain.

HAROLD D. WHITEHEAD, Primary Examiner, 

